On Environmental Economics Tim Haab writes in a comment, “My understanding is that a ton of carbon is a ton of carbon no matter where it is sequestered.”
If only it were so. There is no real definition of “carbon offset”, and the science is weak.
From New York Times,
…I drove a few hours southwest of Omaha to visit Steve Wiese, a 51-year-old farmer who earns extra money by sequestering carbon on his 2,500-acre farm and selling the carbon allowances on CCX. When I arrived, Wiese was going over some paperwork in his barn. On his desk was a check for $2,008.94. “It just came in the mail the other day,” Wiese said, waving it happily.
Wiese, like hundreds of other farmers who are getting paychecks from carbon emitters by way of CCX, practices a form of cultivation known as no-till. Instead of tearing up the fields each spring and releasing the carbon stored in the soil (mostly in the form of decomposing plant matter and roots), no-till farmers plant right over the previous year’s crop, leaving the soil undisturbed.
“How long have you been no-tilling?” I asked him.
“About 14 years,” he said, leaning back in his chair.
“How long have you been getting paid by CCX?”
“Just signed up last year,” he said.
Here was an instance of a major problem that critics of CCX have raised: Wiese is getting paid for storing carbon in his soil, even though he has done nothing to increase the amount of carbon that is being stored on his land — he’s just doing exactly what he’s been doing for the last 14 years.
A description of some other offset projects can be found on Carbonfund.org. They write about their offset projects “you’ll have the option of supporting renewable energy, energy efficiency, reforestation projects, or a combination.”
When it comes to carbon sequestration, there are some snake oil salesmen out there.
The Carbonfund logo says Carbonfund.org: Toward a Zero Carbon World.
Some of my best friends are carbon-based bipeds! A zero carbon world is a terrible idea.